Manned submersible dives reveal a singular assemblage of Hexactinellida (Porifera) off the Amazon River mouth, Northern Brazil.

The outer shelf and upper slope region under the influence of the Amazon River mouth harbors an extensive reef system with a rich sponge fauna, but no hexactinellids were recorded in the area so far. In this work, manned submersibles were used to describe for the first time three species of Hexactinellida off the Amazon River mouth: Hyalonema (Cyliconemaoida) alucia sp. nov., Dactylocalyx pumiceus and Claviscopulia facunda. We found two morphotypes of Dactylocalyx pumiceus, suggesting that it may be a complex of cryptic species. The populations of the three species off Par State were sparse, but a large aggregation of D. pumiceus was found off Maranho State from 145 to 230 m depth. These findings indicate that hexactinellid grounds may be more common along the Northern Brazilian continental outer shelf and slope than previously thought.

Denigrins and Dactylpyrroles, Arylpyrrole Alkaloids from a Dactylia sp. Marine Sponge.

Seven new arylpyrrole alkaloids (1-7), along with four known compounds, were isolated from an extract of a Dactylia sp. nov. marine sponge, and their structures were elucidated by interpretation of NMR and MS spectroscopic data. Denigrins D-G (1-4) have highly substituted pyrrole or pyrrolone rings in their core structures, while dactylpyrroles A-C (5-7) have tricyclic phenanthrene cores. Due to the proton-deficient nature of these scaffolds, key heteronuclear correlations from 1H-15N HMBC and LR-HSQMBC NMR experiments were used in the structure assignment of denigrin D (1). Dictyodendrin F (8), a previously described co-metabolite, inhibited transcription driven by the oncogenic PAX3-FOXO1 fusion gene with an IC50 value of 13 µM.

A collection of hexactinellids (Porifera) from the deep South Atlantic and North Pacific: new genus, new species and new records.

This article describes or redescribes four hexactinellid sponges, namely Poliopogon amadou, Euplectella sanctipauli sp. nov., Bolosoma perezi sp. nov. and Advhena magnifica gen. et sp. nov. P. amadou, E. sanctipauli sp. nov. and B. perezi sp. nov. represent new findings for the South Atlantic deep-sea fauna, including the first record of Bolosoma for this ocean. Advhena magnifica gen. et sp. nov., on the other hand, was collected by NOAA oceanographic expeditions in the North Pacific (Pigafetta Guyot).

Two new Hamacantha (Vomerula) from the Rio Grande Rise (SW Atlantic (Hamacanthidae, Porifera).

Hamacantha occurs worldwide and frequently in deep-waters. It is easily distinguished from any other sponge by the possession of conspicuous diancistra microscleres. Here we describe two new species from the Rio Grande Rise. Hamacantha (Vomerula) jeanvaceleti sp. nov. is the sole Hamacantha with styles, diancistras in two categories with the smaller ones cyrtancistra-like; and H. (V.) klausruetzleri sp. nov., the sole with two types of megascleres (styles and strongyles), two categories of diancistras, and two categories of sigmas.

Hamacantha (Hamacantha) boomerang sp. nov. from deep-sea coral mounds at Campos Basin, SW Atlantic, and redescription of H. (H.) schmidtii (Carter, 1882) (Hamacanthidae, Poecilosclerida, Demospongiae).

There are 22 species of Hamacantha registered from all over the world, and frequently from deep-waters, only two of which had previously been reported from the SW Atlantic. Here we describe a third species for this area, Hamacantha (H.) boomerang sp. nov., collected from deep-sea coral mounds at Campos Basin (off Rio de Janeiro state). We found oxeas 271-630 µm long, diancistras in three size classes, 125-155, 45-69 and 20-29 µm, and toxas, 58-82 µm. This is the only Hamacantha combining oxeas and toxas, but the latter are very rare. The species approaches the Caribbean H. (H.) schmidtii (Carter, 1882), where we observed oxeas 390-495 µm long, and diancistras in three size classes, 109-124,  44-54 and 26-41 µm, however toxas appear to be absent. Both species are clearly distinct by micrometric values, as well as the overall morphology of the smaller diancistras, distinct from the intermediate category in the new species, but quite similar in H. (H.) schmidtii. Hamacantha (Vomerula) falcula approaches the new species very closely in microsclere dimensions and morphology, but is set apart by its styloid and smaller megascleres.